A liquid crystal display device, such as a liquid crystal television, for example, requires a separate backlight device as an illumination device since a liquid crystal display panel, which serves as the display panel thereof, does not emit light independently. A backlight device for this type of liquid crystal display device, depending on the mechanism thereof, is roughly categorized into a direct-lit type and an edge-lit type. For the purpose of achieving a thinner liquid crystal display device, the edge-lit backlight device is considered preferable.
In a known configuration of an edge-lit backlight device, a fixing member is provided to affix a substrate, on which a light source such as an LED or the like is mounted, to a light guide plate. By using the fixing member to keep the distance between the light source and the light guide plate constant, this configuration improves the utilization efficiency of light emitted by the light source, and prevents and suppresses display unevenness on the display surface. A backlight device with such a configuration is described in Patent Document 1, for example.